Gas filter mats



Jan. 20, 1959 A. c. FIELDS 2,869,680

GAS FILTER MATS Filed Sept. 50, 1957 2 Sheets-Sheet l Jan. 20, 1959' A Q FIELDS 2,869,680

GAS FILTER MATS United lStaes 12,369,680 GAS FILTER MATS Arnold C. Fields, Medield, Mass.,assignor to Westinghouse Electric Corporation, East Pittsburgh, Pa., a corporation of Pennsylvania ApplicationSeptember 30, 1957, Serial No. 687,325

1o Claims. (ci. 18s- 62) This invention relates to filters for removing small foreign particles such as dust, from gases such as air.

Fibrous mats are widely used for cleaning air, and it is common practice to placea clean mat roll on one side of an `air passage; to place a rewind roll on theother side of the air passage, and to unroll a clean mat section from the supply roll to extend across the air passage, while at the same time rolling up a corresponding dirty mat section `on the rewind roll.

passages with flat upstream and downstream surfaces.

This invention provides a mat supply roll which has a mat so folded thereon that it can be unfolded as it leaves the supply roll so as to have a zig-zag outline where it` to form a zig-zag filter.

. Another object of this invention is to provide a folded filter that can be rolled up on a supply roll; can be unfolded to form a zig-zag filter, and can be rerolled on ,a rewind roll. ,Y

This invention will now be described with reference to the annexed drawings, of which:

Fig. l is a projected view of a filter mat folded and rolled up intl accordance with this invention;

` Fig. 2 isa side` elevation, partially in section, of a gas` cleaning system embodying this invention, the adjacent side of the air duct enclosing the zig-zag ilterbeing removed;` i

Fig. 3 is a section along the line 3--3 of Fig. 2;

Fig. 4 is agback view on 'a reduced'scale of the mat supply roll and `of the back guide ingersof` Figs. 2 and 3 withtheirouter ends located in the passages in the outer side of the mat;

Fig. 5 is a view similar to Fig. 4 but omits the back guide ingersand shows, instead, the front guide ngers with their outer ends located in the passages in the inner side of the mat, and Y K Fig.- 6 isa fractional projected viewlooking at the upper portion of the gas inlet side of the system.

Fig. 1 shows a mat supply rol1f10 embodying this invention. A rewound., roll wouldbeasimilar. brous mat of felt, glass wool or other type of fibrous mat commonly used for cleaning air, has its edges yfolded over to form edge beads 11; is folded between its edges Heretofore, in such systems, the mat sections have extended across the air `atent 0 i Patented Jan. 20, 1959 The `folded i mat is being slidable in these slots. A rewind roll 25 similar to the supply roll 10, is on a rotary shaft 26 journalled in bearings 27 which have arms 28 which contact the` inner ends of coiled springs 29, the outer ends of which t contact spring supports 30 on the frame 21. Theframe 21 has arms 31 with slots 32 in which the shaft 26 is slidable.

Thesupply roll 10 and the rewind roll 25 are on oppositetsides of an air duct 34. The duct 34 has upper and lower walls 35 having zig-zag openings shaped to closely conform with the zig-zag outline of a mat section to pass therethrough so as to minimize air leakage. The` duct has side walls 36. A pair of spaced apart plates 37 extend across the duct between the walls 36 at the up-` stream or air inlet side of the iilter section, and a similar pair4 of spaced-apart plates 3S extend across the duct between its side walls 36 at the downstream or air outlet side of the filter section.

Attached tothe plates 37 `are spaced-apart, horizontally extending rods 40 which are attached at their inner ends to rods 41 which have vertically extending central portions, and have upper portions 42 which `extend in Vs from their central portions, being slanted towards the upper plate 38. The rods 41 have lower portions 42A t which extend in inverted Vs from their central portions,

to form three, inner,` at pleats 12 which have parallel` i passages 14 between the pleats 12 and between the outer pleats 12 and the beads 11, and is folded between its edges to form four, outer, at pleats 13 which have parallel passages 15 therebetween. The inner pleats overlap being slanted towards the lower plate 38.

Attached to the plates 38 are spaced-apart,jhorizo-ntally` extending rods 43 which are attached at their inner ends to rods 44 `which have vertically extending central `,portions, and have upper portions 45 which extend in Vs.` from their central portionsfbeing slanted towards the upper plate 37. The rods 44lh'ave lower portions 445A which extend in `inverted Vs from their central portions,v being slanted towards the lower plate 37.

The V-shaped rod portions 42 and 45 are guide fingersr for causing a mat section fro-m the roll 10 to unfold in a zig-zag outlinefand the V-shapedirod portions 42A and` 45A are guide fingers for causing a zig-zag matfsection to refold `so as to be rewound on the roll 25. f i

The upper ends of the guide lingers 42 extend into the passages 15 in the mat on the roll 10 and contactthe adjacent sides of themat pleats 12, causing, due tothe forward` slope of the guideiiingers 42, the mat pleats 1,2 they contact to be deflected forwardly into the Vs between the fingers 42to a maximum deflected position Where their apices Contact the central vertical portions of therods `44,'1when the first length of mat is drawn over the uppersends ofthe guidelingers 42 and` 45. `The upper ends of the guide iingers 45 extend into the pas-` sages 14 incontact with the adjacent` sides of themat pleats 13, causing, due to the rearwardslope `of the guide iingersi, thel mat pleats 13 they Contact to-be deflected rearwardly` into the Vs between the lingers 45, ,to aV Aftera period'of use sutiicient for the zig-zag 4mat i i section in the duct 34 to have become loaded with dust,

the rewind roll 25 would be rotated as by a crank-arm that is not shown, in a direction to rewind the dirty mat section on the roll 25, and to supply a new mat `section Y the fingers 45A contact the mat section.

assesses itis'folded on they supply roll as shown by Fig. l.

yendsof the guide-fingers@L and 45vas the-.diameter of thetsupply roll decreases, and soaslto maintain the'rnat, section: bein'gwrewound onthe rewind roll 25 in-the same position relative thefl'ower ends ofthe guidevfingers 42A and`-45A.as the diameter of the rewind roll 25 increases;

The-supplyand rewind rolls could, of course, be located within the air duct 34.

What is claimed is:

1. A filter comprising a roll of fibrous mat, said mat beingfolded in a plurality of spaced-apart pleats at the innerside thereof and in a plurality of spaced-apart pleats atf the outer side thereof, there being a first plurality of passages vbetween said pleats at said inner side and a second plurality .of passages between said pleats at said outer side, means for supporting said roll for rotation, and means for unfolding said mat in a zig-zag outline when itleaves said roll when saidroll is rotated in adirection tounroll said mat, said means comprising a first plurality of V-shaped: guide ngers at said inner side of said mat, said yfingers having their diverging ends in saidl passages of said first plurality, and a second plurality of Vshaped guide fingersat saidy outer side` of said mat, said fingers of said second plurality of fingers having theirdiverging ends in said passages of said second plur-ality ofpassages, said lfingers of said first plurality of fingers being slanted towards said fingers of said second plurality of fingers, and said fingers ofsaid second plurality of lingers being slanted towards said fingers of i sai'clfirstplurality of fingers. f v

' V2". A-iilter-as claimed in claim l inwhich the edges of said'mat are folded in beads, and inwhich means is provided for receivingiand guiding said beads in parallel lines as-said mat leaves said roll.

3.*A'filter as claimed in claim 2 in which said means for supporting said roll for rotation comprises a rotary shaft, means for slidably supporting saidV shaft for movement towards and from said ends of v-said fingers, and resilient means-for urging said shaft towards said ends of saidv fingers. f

'4. Ay filter as -claimed in claim 3 vin which means--is provided for maintaining said mat-in zigzagloutline after leaves fsa'id fingers comprising straight, parallel guide members in the apices of jsaid unfoldedmat on opposite s'idesthereof;Y

5.Aj filteras'A claimed in claim l-,inA which meansis provided for maintaining said mat in zig-zag outline afterit leaves said fingers comprising straight, parallel l guide members yinthe apice'sof said unfolded mat on vided for receiving and guiding` said beads lines as said mat leaves saidtroll. g

7. A filter as claimed in claim l in which said means for supporting said roll for rotation comprises a rotary shaft, means for slidably supporting said shaft for movement towards and from said ends of said fingers, and resilient means for urging said shaft towards said ends of said fingers.

8. A filter comprising a supply roll of fibrous mat in parallel .f located on one side of` a gas passage, a rewind'roll for" said mat located on the opposite side of said passage, means forsupporting said'rolls for rotation, said mat being folded on said supply rollin a--plurality of-spaced apart pleats at the inner side thereof and in a plurality of spaced-apart pleats at the outer side thereof, there being .a first plurality of passages between said pleats at said inner sidev and a second plurality of passages between saidpleats atsaid outer side,.1n`eansfor unfolding saidzmatV in avzigzag-outline when itleaves lsaid supply roll-when saidV rolls are; rotated. insa direction to unroll a sectionofssaid mat fromvsaidl supply roll and to-wind amat section on; saidrewind rol-1,L said unfolding'means comprising afirst plurality of V-shaped guide fingers at said inner side of said mat, said fingershaving their diverging endsrin said passages of said first plurality, and afsecond pluralityfofL V-shaped guide fingers at said outer sideof said mat, saidfingers of said secondl plurality hav..- ingV their diverging ends insaid passages of said secondA plurality, said fngersifof said second. plurality having theirrdiverging ends insaid passages of said second plu rality, saidl fingers of said first plurality being slanted towardsfsaid fingers of said second pluralityand said I* fingers offsaid second plurality being slanted towards lclaim 5 in which the-edgesfof Y Y said fingers of said first plurality, and means for re-folding a mat section asit passesontosaidrewind roll, saidre-foldingf meansV comprisingV a firstj plurality ofvinverted V-shaped guidefingers at the inner side 'of s aidmat section at said:V rewind roll having their diverging ends aligned with said diverging 'ends of said fingersy of'said first= pluralityof- V-shapedl fingers, and a secondV yplurality ofl inverted V-shaped guidefingers -atthe outer side-of said mat section at said rewind roll having .their 'diverge ingendsy aligned with said diverging endsofrsaidi-fingers ofsaid second plurality of V-shaped-guide'fi-ngers, said' inverted;- V-shapedA fingers ofA saidfirstf plurality being slanted towards said inverted V-shaped` fingers ofV said'A second plurality, and said inverted V-shaped finger-s of said second plurality beingeslantedtowards said' inverted V'shaped-fingers of said first -plurality..r

9. A filterV asclaimed in claim 8 inl whichrthe edges of said'mat are foldedin-beads, 'andin-whichmeansis provided for guiding said beads'in parallelflines betweenl saidl rolls@ Y' t l0. A filter asl claimed in claim 9in which saidsmcans for supporting said' rolls lfon-rotationA eornprises-4 rotary shaftsf'fmeans- 'forslidablyf4 supporting said "s'haftsf for movementaitowards and1-fro m saidA guide-{fing =.rs,1 andi resilientrneanswforurgingasaid 1shaft'stowards-fsaid guide fingers. Y 1

I* References Citedl-inthe le of'tli'ispatenty UNITED" STATES PATENTS* 

